Engines, including diesel engines, gasoline engines, natural gas engines, and other engines known in the art, may exhaust a complex mixture of air pollutants. The air pollutants may be composed of gaseous and solid material, which include particulate matter. Particulate matter may include unburned carbon particles, which are also called soot.
Due to increased attention on the environment, exhaust emission standards have become more stringent. The amount of particulates emitted from an engine may be regulated depending on the type of engine, size of engine, and/or class of engine. One method that has been implemented by engine manufacturers to comply with the regulation of particulate matter exhausted to the environment has been to remove the particulate matter from the exhaust flow of an engine with a device called a particulate trap. A particulate trap is a filter designed to trap particulate matter, and consists of a wire mesh medium. However, the use of the particulate trap for extended periods of time may cause the particulate matter to buildup in the wire mesh, thereby causing the functionality of the filter and engine performance to decrease.
One method of improving the performance of the particulate trap may be to implement regeneration. For example, U.S. Pat. No. 6,572,682 (the '682 patent) issued to Peter et al. on Jun. 3, 2003, describes using a self-cleaning filter system to remove particulate matter from an exhaust flow of an engine. The filter system of the '682 patent is designed for use in a diesel engine and comprises a filter media stack having a plurality of sub-cartridges. Exhaust flow is directed through each of the sub-cartridges via damper valves, to remove particulate matter from the exhaust flow. A heater is used to increase the temperature of the sub-cartridges and the trapped particulate matter above the combustion temperature of the particulate matter, thereby burning away the collected particulate matter and regenerating the filter system.
Although the filter system of the '682 patent may reduce the particulate matter exhausted to the environment and reduce the buildup of particulate matter in the filter system, the filter system may be complex and costly. In addition, the large size of the filter system of the '682 patent may be incompatible with the limited space within an engine compartment.
The present invention is directed to overcoming one or more of the problems set forth above.